2023-01-24

09:30:Machine setup

11:12 We will run the nominal KURNS AWG script first to make sure the machine is working as expected

11:57:machine working starting rebunching test

12:10 - RF offset timing is set to 2.110 ms

Note: While making the rebunching RF scripts I noticed that the adiabatic AWG script RF voltage only changes once phis has already reached zero in Shinji's Schottky AWG scripts. I was under the impression that the RF voltage reduces to 1kV at the same time phis goes to zero.

For the re-capture AWG scripts I have mirrored Shinji's schottky AWG scripts, see screenshot below.

• The screenshot below show an example recpature AWG script with 5ms coast

We observed signal on the FAB after rebunching particularly in the adiabtic case. So there was beam left over from the previous cycle in last week's data.

Method to remove left over beam: We have made AWG scripts for the schottky measurement which recapture and accelerate the beam to ~81 Mev and into the scraper to remove the previous beam.

• 30ms of coast between debunch and recapture+acceleration

• RF shaker would take c. 1hr to install

15:05 begin measurement series schottky with beam killing programme (see screenshot below)

• current scraper position 505mm /0055663

• Loading awg scripts

RF offset changed to 2.136 ms for 10 Hz rep rate

Start taking data for schottky measurments with an RF program to kill any remaining beam

set scraper position so that beam loss is clear after recapture at t=60ms

• set at original position of 505mm /0055663 - see beam loss on the FAB at this point

Recording beam loss data (i.e. fab data showing loss of beam on scraper)

In the schottky scripts with beam removal, the coasting section ie the section where we take schottky data is 30 ms, we think that should be enough to get enough resolution for the FFT

Did not see any FAB signal in the reacceleration section for the 4kv abrupt case with the 30ms of coast

15:55 Oscilloscope rebooted

Did not see any FAB signal in the reacceleration section for the 3kV case with 30ms of coast.

This morning we did see some FAB signal after 30 ms of coast and recapture in the 4kV case. The RF program from this morning recaptures into a stationary bucket. The program we are using to remove the previous beam for the schottky measurements recaptures the beam and accelerates it into the scraper at ~80MeV. When we recapture and then ramp phi_s to accelerate, the bucket area decreases. This could be the reason we do not see any signal on the FAB for the 4kV case after 30ms of coast with this afternoon's measurements.

Recaptured particles that are lost during the phi_s ramp in the reacceleration phase will continue to coast round the ring (hopeully) at a different frequency to the next beam, ie the revolution frequency peak in the schottky spectra will be uneffected (hopefully)

Finished taking schottky data with RF program to remove remaining beam